Exam 4 Pre test

List the products of glycolysis. (Module 23.3A)

2 molecules of pyruvate, 2 molecules of ATP, 2 molecules of NADH

Describe a portal triad. (Module 22.21B)

A portal triad consists of an interlobular vein, an interlobular artery, and an interlobular bile duct.

Compare catabolism and anabolism. (Module 23.1A)

Catabolism is the breakdown of large molecules into smaller ones, whereas anabolism is buildup of large molecules from smaller building blocks.

Distinguish between chemical digestion and absorption. (Module 22.5B)

Chemical digestion involves the breakdown of food, whereas absorption involves the movement of nutrients across the digestive epithelium into the interstitial fluid.

How do the absorptive and postabsorptive states maintain normal blood glucose levels? (Module 23.13C)

During the absorptive state, insulin stimulates glucose uptake by cells and during the postabsorptive state, glucagon stimulates the breakdown of glycogen to form glucose.

Identify the fates of fatty acids. (Module 23.11C)

Fatty acids may become a fuel source or a component of triglycerides, glycolipids, phospholipids, prostaglandins, cholesterol, and steroids.

How would the pH of the intestinal contents be affected if the small intestine did not produce secretin? (Module 22.14B)

It would be more acidic than normal

Describe the roles of LDLs and HDLs. (Module 23.10C)

LDLs deliver cholesterol to tissues and HDLs absorb unused cholesterol and return it to the liver.

What two coenzymes transfer hydrogen atoms to the electron transport chain? (Module 23.4C)

NAD and FAD

How does digestion occur in the large intestine? (Module 22.17A)

No digestive enzymes are produced in the large intestine but digestion continues from the enzymes present that were secreted or produced in the small intestine.

Describe the alkaline tide. (Module 22.11C)

The alkaline tide is the sudden influx of bicarbonate ions into the bloodstream.

Briefly describe the citric acid cycle, and explain its role. (Module 23.4A)

The breakdown of organic molecules to release hydrogen atoms bound to coenzymes that can enter the electron transport chain.

Distinguish between the exocrine and endocrine secretions of the pancreas. (Module 22.18B)

The exocrine pancreas produces buffers and enzymes and the endocrine pancreas produces hormones.

Describe two central reflexes triggered by stimulation of the stretch receptors in the stomach wall. (Module 22.15B)

The gastroenteric reflex stimulates motility and secretion in the small intestine and the gastroileal reflex opens the ileocecal valve.

Define oxidative phosphorylation. (Module 23.5A)

The generation of ATP through the transfer of electrons from coenzymes to oxygen.

Explain the significance of the alkaline mucous layer lining the interior surface of the stomach. (Module 22.11A)

The mucous layer protects epithelial cells from the acid and enzymes in the gastric lumen.

Explain the function of lacteals. (Module 22.12C)

They transport materials that cannot enter blood capillaries.

When and how do ketone bodies form? (Module 23.13B)

during the postabsorptive state when lipids and amino acids are broken down by the liver

Most of the absorbed nutrients enter into which blood vessel? (Module 23.8C)

hepatic portal vein

Which accessory organ of the digestive system is responsible for almost 200 known functions? (Module 22.18C)

liver

Define stellate macrophages, and indicate their functions. (Module 22.21C)

liver macrophages which engulf pathogens, cell debris, and damaged blood cells

Which is more efficient in propelling intestinal contents along the digestive tract: peristalsis or segmentation? Why? (Module 22.4A)

peristalsis; because it involves pushing the bolus forward

Which other systems work with the digestive system to support the cells and tissues of the human body? (Module 22.1A)

respiratory, cardiovascular, and urinary systems

Identify the structural characteristics of smooth muscle fibers. (Module 22.3B)

spindle shaped fibers that lack T tubules, myofibrils, and sarcomeres

List the accessory organs of the digestive system. (Module 22.1C)

teeth, tongue, salivary glands, liver, gallbladder, pancreas

What happens to the ammonium ions that are removed from amino acids during deamination? (Module 23.12C)

they combine with CO2 and enter the urea cycle

If vitamins do not provide a source of energy, what is their role in nutrition? (Module 23.14C)

they serve as coenzymes in metabolic pathways

What is the importance of the mesenteries? (Module 22.2A)

they support and stabilize organs of the abdominal cavity and provide a passageway for blood vessels, nerves, and lymphatic vessels

What is the primary digestive function of the pancreas? (Module 22.23A)

to produce buffers and enzymes for the digestion of starches, lipids, nucleic acids, and proteins

In amino acid metabolism, identify the processes by which the amino group is removed. (Module 23.12B)

transamination or deamination